Step 1: Abi walks 10 km North, so he is 10 km north of the starting point. Step 2: He then walks 6 km South, which brings him back to 10 - 6 = 4 km north of the start. Step 3: He then walks 3 km East, so his position is now 4 km north and 3 km east of the starting point. Step 4: This forms a right triangle with legs 4 km and 3 km. Using the Pythagorean theorem, distance = √(4² + 3²) = √(16 + 9) = √25 = 5 km. So Abi is 5 km from his starting point.